Now my old setup/recipe does not work. 1. Append to kernel parameters "8250.nr_uarts=8"After reboot I have got serial nodes up to ttyS72. Using lspci output decide port addresses and irq configure /etc/serial.conf/dev/ttyS4 uart 16550A port 0xd100 irq 20 baud_base 115200 spd_normal skip_test ^fourportone raw for each port, only port is different.In Debian 9, using this setup I have got:$ setserial /dev/ttyS4 -aInvalid argumentSame for every four ports.After several hours of work I have got that the /dev/ttyS4 .. 7 is the "Invalid argument itself".As a "work around" I was clean /etc/serial.conf and used a script started form rc.local:

One raw for each port, with the same sequence. The third settings are aimed from BrainBoxes script.The card start working well - I have got checked using short pins 2-3 of DSUB plug, Also other box as a serial terminal and using minicom (9600 baud w/o handshake).But the resultsa, what system is reported at least false.

As you can mention, my card is using irq 0 !? /proc/interrupts reporting that irq 20 does not used at all.What is this bug could be? What package should be reported? May be it is kernel? - but on kernel.org you can not send bug about linux 4.9.0 amd64